Tell me about it. How many makers other than Kickbike™ and Footbike™ even use 18″ wheels? (As far as I know, only Birdy folding bicycles.) A survey of this page reveals a scarcity of 18″ wheels among the products.
Well, I’d like to see a 2x700C” footbike for the mass market (such as it is). Apart from the frame, there wouldn’t be one component you couldn’t buy in any ordinary bike shop. You wouldn’t have to double up on spare tubes and tires (two sizes) for rides. If you wanted to race, you could get yourself a proper set of sew-ups.
Stepteam High Level, which uses some Groeneveld carbon 2x700C’s, also use some bikes with extensions on the original short rear forks to accommodate 700C rear wheels. Those extensions would make a nice aftermarket product.
I weep for the Sidewalker City! The promises of an elegant frame are dashed by a crazy deck height. 24″ replacement wheels might have a shot at lowering everything an inch if it weren’t for the direct-pull-brake anchors on the forks.
No, my 2x700C will have quality medium-reach sidepull brakes – and a threaded headset!